Driven by consumer preference, the dairy industry is constantly striving to achieve minimally processed foods which are free from artificial preservatives. In this context, much attention is being directed to preventing growth of and/or killing of Listeria spp. and/or Clostridia spp. with the use of bacteriocins produced by microorganisms that are generally recognized as safe (GRAS), including many lactic acid bacteria (LAB). Bacteriocins are ribosomally synthesized anti-microbial compounds that are produced by many different bacterial species. Lacticin is a known bacteriocin, e.g. from WO 96/32482, and is known to be active against Gram-positive bacteria.
Methods for making Swiss-type cheeses are e.g. known from WO 01/70037, U.S. Pat. Nos. 4,242,362, 5,006,348 and WO 2006/098972. In known methods for making Swiss-type (or Gouda-type) cheeses, pathogen contamination is prevented by adding lysozyme or nitrate to the cheese milk, nitrate rinsing of the curd and/or bactofugation. For a further explanation (on Gouda-type cheese), see e.g. Van den Berg et al. in Cheese: Chemistry, Physics and Microbiology, Third edition—Volume 2: Major Cheese Groups, 2004, 133-134. These methods are undesirable for a number of reasons including environmental or legal aspects or reasons of process efficiency.